A Clinical Study About The Different Current Intensity Of Electroacupuncture For Preventing Chronification Of Acute Pain Of Knee Osteoarthritis( KOA ) Patients

Objective: Pain can be divided into acute pain and chronic pain according to the duration of the pain. Clinical researches in the past indicated that acute pain could be treated effectively by electroacupuncture(EA), but it has not solved the clinical problem of long-term recurrence of pain after chronification of acute pain. Diffuse injury inhibitory controls(DNIC) function is now recognized as a reliable indicator to predict chronic pain events risk. Previous studies have proved that DNIC function of knee osteoarthritis(KOA) patients would decline with the progress of chronic pain gradually. Our target of this study is to find whether EA can prevent chronification of acute pain of KOA by improving impaired DNIC function, and then compare the curative effect of different intensity of EA. Finally, rich the clinical theory study about EA analgesia and improve the clinical curative effect of chronic pain.Methods: A total of 91 KOA patients(2 out among them and 2 fall off among them) came from the acupuncture inpatient and clinics of six hospitals(Combined traditional Chinese and western medicine hospital, Wuhan Hospital of traditional Chinese medicine, Central hospital of Wuhan, The third Hospital of Wuhan, The fifth Hospital of Wuhan and Union hospital, Huazhong University of science and technology) were randomly divided into three different intensities of EA group according to doctor order as follows: Strong EA group received EA with high-intensity current(2m A<current<5m A) on the ipsilateral “ Neixiyan ”(EX-LE5), “ Dubi ”(ST35), “Liangqiu”(ST34) and “Xuehai”(SP10). Weak EA group received EA with low-intensity current(0m A<current<0.5m A) on the same points. Sham EA group received EA with low-intensity current(0m A<current<0.5m A) with fine needles which inserted superficially into the points 1cm lateral to above points. The patients will be treated with EA once every day, 5 times as a course, totally treated with 2 courses and one day between treatments as interval. DNIC function of the spontaneous pain, DNIC’ function of the induced pain, Numerical Rating Scale(NRS) and Emotional Scale(ES) were detected before treatment, the fifth and tenth treatments.Results:(1)The basic information including gender, age and course of the disease et al of the three groups before trial have no difference(P > 0.05).So they were comparable.(2)All indexes before and after the intervention of strong EA group have a difference(P<0.05) and DNIC’, NRS, ES have significant difference before and after therapy(P < 0.01).(3)All indexes before and after the intervention of weak EA group have a difference(P<0.05) too.(4)The values of DNIC and DNIC’ before, during and after treatment of sham EA group have no difference(P > 0.05) which were not comparable. But the values of NRS and ES both have difference before and after intervention(P < 0.05).(5)The DNIC functions of two true EA groups after the task were significant(P<0.05) in statistically.(6)The value of NRS during and after intervention of strong EA group and sham EA group were significant(P<0.05) in statistically.Conclusions:(1)EA can inhibit chronification of acute pain of KOA patients.(2)EA can repair impaired DNIC function during chronification of acute pain of KOA patients effectively.(3)Strong EA and weak EA both can improve the damaged DNIC function of KOA, they also can improve the participants’ pain and bad mood. But Strong EA is more effective in improving impaired DNIC function for KOA patients and the analgesic effect is more prominent.(4)Sham EA can improve the patient’s pain and bad mood, but cannot improve impaired DNIC function of KOA patients.(5)Strong EA, weak EA and sham EA all can improve the patient’s pain and bad mood, but strong EA will improve the effect of the best, sham EA will improve the result of the worst.